Question

我必须阅读我有权阅读的（sudo）远程文件的内容猫，少或尾。

我将在Ruby中执行此操作，因此我假设我应该使用Net :: SSH来执行此操作。

该文件是一个日志文件，所以它可能非常大。

这是我现在正在尝试的代码：

require 'rubygems'
require 'net/ssh'

cmd = "sudo cat /var/logs/httpd/ACCESS_log.2012.03.23"

Net::SSH.start( "SERVER" , "USER", :password => "PASSWORD") do |ssh|
  ssh.open_channel do |channel|
    channel.request_pty
     channel.exec(cmd);

     channel.on_close do
       puts "shell terminated"
     end
    channel.on_eof do |ch|
      puts "remote end is done sending data"
    end
    channel.on_extended_data do |ch, type, data|
      puts "got stderr: #{data.inspect}"
    end
    channel.on_data do |channel, data|
      if data =~ /^\[sudo\] password for USER:/
        puts "data works"
        channel.send_data 'PASSWORD'
      end
     channel.on_data do |ch,data|
        puts "in third"
        puts data.inspect
     end
    end
   channel.on_process do |ch|
     puts "in process"
   end
  ssh.loop
  end
end

当我运行时，我得到以下输出：

正在进行中正在进行中正在进行中数据有效正在进行中正在进行中正在进行中在第三 “\ r \ n” 远程端完成发送数据 shell终止

日志实际上当前有几千行数据，因为我可以使用putty从实际服务器读取它。

如何从channel.on_data中获取结果？

由于

Answer 1

我认为您需要在发送的密码中添加\n。这适合我。注意，在我注释掉else子句的地方，你也可以从那里获取信息，但它可以正常工作，但密码中有\n。

require 'rubygems'
require 'net/ssh'

cmd = "sudo cat /var/log/mail.log"
HOSTNAME = "myhost.example.com"
USERNAME = "me"
PASSWORD = "12345"


Net::SSH.start( HOSTNAME , USERNAME, :password => PASSWORD) do |ssh|
  ssh.open_channel do |channel|
    channel.request_pty
     channel.exec(cmd);

     channel.on_close do
       puts "shell terminated"
     end
    channel.on_eof do |ch|
      puts "remote end is done sending data"
    end
    channel.on_extended_data do |ch, type, data|
      puts "got stderr: #{data.inspect}"
    end
    channel.on_data do |channel, data|
      if data =~ /^\[sudo\] password for #{USERNAME}:/
        puts "data works"
        channel.send_data "#{PASSWORD}\n"
      else
        #puts "OUTPUT NOT MATCHED: #{data}"
      end
       channel.on_data do |ch,data|
         puts "in third"
        puts data.inspect
       end
    end
   channel.on_process do |ch|
     puts "in process"
   end
  ssh.loop
  end
end

Answer 2

您正在执行on_data回调时替换新的on_data回调。我没有考虑Net :: SSH的内部，但这可能会产生令人惊讶的行为。

尝试将两个on_data回调中的代码更改为一个，看看是否有帮助。

channel.on_data do |channel, data|
  if data =~ /^\[sudo\] password for USER:/
    puts "data works"
    channel.send_data 'PASSWORD'
  else
    puts "in third"
    puts data.inspect
  if
end

作为旁注，由于您需要sudo来阅读日志，因此有人认为他们和该服务器值得保护。看起来你正在嵌入密码，这些密码可以在这个ruby程序中提供对服务器的特权访问。这意味着任何能够阅读该程序的人都可以获得相同的特权访问权限。您将如何限制在此程序中访问密码？

Answer 3

require 'net/ssh'

Net::SSH.start('host', 'user', :password => "password") do |ssh|
  # capture all stderr and stdout output from a remote process
  output = ssh.exec!("hostname")
  puts output

  # capture only stdout matching a particular pattern
  stdout = ""
  ssh.exec!("ls -l /home/jamis") do |channel, stream, data|
    stdout << data if stream == :stdout
  end
  puts stdout

  # run multiple processes in parallel to completion
  ssh.exec "sed ..."
  ssh.exec "awk ..."
  ssh.exec "rm -rf ..."
  ssh.loop

  # open a new channel and configure a minimal set of callbacks, then run
  # the event loop until the channel finishes (closes)
  channel = ssh.open_channel do |ch|
    ch.exec "/usr/local/bin/ruby /path/to/file.rb" do |ch, success|
      raise "could not execute command" unless success

      # "on_data" is called when the process writes something to stdout
      ch.on_data do |c, data|
        $stdout.print data
      end

      # "on_extended_data" is called when the process writes something to stderr
      ch.on_extended_data do |c, type, data|
        $stderr.print data
      end

      ch.on_close { puts "done!" }
    end
  end

  channel.wait

  # forward connections on local port 1234 to port 80 of www.capify.org
  ssh.forward.local(1234, "www.capify.org", 80)
  ssh.loop { true }
end

使用ruby Net :: SSH通过sudo读取远程文件

3 个答案: